Sewer trap



Jul? E. ,J. PRESCOTT ,3

SEWER TBA? Filed April 5, 1943 Smaentor v verei c I. Prescofi witness 8B H bert C. Covgg CKitorneg Patented Jan. 11, 1944 UNITED STATE PATENT OFFICE 8 Claims.

This invention relates to a sewer trap and more particularly to a device used in the manhole of a sewer system for trapping roots and other large bodies as well as sand and sediment that has lodged in the sewer pipe.

One method of cleaning a sewer pipe is to force a power driven cutting device through the sewer pipe from one manhole to the other and thus to cut off roots that have worked through the joints between the pipes and to dislodge grease and other solid bodies obstructing the pipe. The obstructions are forced towards the second manhole where an attempt is made to catch the material and remove it manually. For trapping sand, it has been customary to use an elbow shaped metal pipe, one end of which open:- upwardly while the other fits into the exit pipe of a given manhole. This traps ant sand or other matter that will not flow over the upper open end of the pipe. A head of water at an upper manhole of the system is employed to wash the sand down toward the elbow trap. This device is not suitable, however, for trapping the roots and other large objects that may also be in the pipe line, since the roots and other obstructing material which float with the water may either escape through that elbow pipe or plug it up and prevent a proper flow of the water. Various problems such as these have made the cleaning of a sewer system a difiicult and arduous task.

The ordinary construction of a sewer manhole comprises a substantially cylindrical chamber large enough for men to work therein. The inlet and outlet sewer pipes open into the chamber of this manhole at its opposite sides and near the bottom. A substantially U-shaped open channel connects these two pipes, so that the sewage normally flows through this channel between two shelves or ledges on which men may stand while working in the manhole.

In accordance with my invention, I have provided a trap arranged to fit within and above the channel within the manhole, and which permits the water to flow readily through the channel, while at the same time entrapping roots and other large obstructions. The device is so constructed that sand and other fine material may be likewise trapped while at the same time permitting ready egress of the sewage fluid.

The primary object of my invention is to provide a sewage manhole trapping device which will serve the double purpose of either catching roots and. other large bodies or of entrapping the finer materials, such as sand, and which may be readily installed and removed and will operate efficiently for the desired purposes.

A further object of the invention is to provide a portable sewage trap of such a construction and arrangement that it will fit automatically within various sized channels of sewer pipe manholes, so that a single device may be used throughout a sewage system having many sizes of pipe lines.

A further object is to provide a construction of this type which may be used to entrap only the coarser materials and permit the ready flow of water therethrough or which may be arranged to form a weir for entrapping finer solid matter and wherein ready escape of the water over the weir is permitted. Further objects will be apparent in the following disclosure.

Referring to the drawing:

Fig. l is an isometric view of thedevice installed over a sewer channel and arranged for trapping roots;

Fig. 2 is a side elevation of the device;

Fig. 3 is a top plan View, partly broken away, showing the arrangement of sewer pipes andthe trap in a manhole;

Fig. 4 is an isometric view, corresponding'with Fig. 1, in which the sand trapping plates are in place; and

' Fig. 5 is an isometric view of the sand trapping plates assembled in their proper locations apart from the frame work of Figs. 1 and 4.

The preferred form of sewer trap as shown in the drawing comprises two substantially U- shaped flanged supports Ill and I2 made of angle irons and arranged one above the other, but with the lower support I! somewhat longer and extending forward of the upper one. These angle iron supports are connected together by a series of vertical metal strips 14 suitably riveted or welded thereto so as to form a rigid frame. The upper angle iron support ID has a horizontal portion or plate l5 and a vertical flange l6. Similarly, the lower support l2 has a vertical flange I! and a horizontal plate I8. I

A primary feature of this invention comprises spaced rod 20 and 21 which are arranged substantially vertically between these two flanged supports or frame members I0 and I2; and they preferably extend upwardly above the upper support. These rods are of such size, shape and arrangement that they will trap the ordinary forms of roots and lumps of grease and other large bodies of solid matter that may be floating down with the sewage. The rods 20 are preferably secured rigidly in position by any su.table means, such as by welding or merely by making a tight fit within spaced holes in the horizontal plates l5 and 8 of the two side arms of the frame members It and I2. They project well above the upper plate I5 so as to provide a proper trap when water pours over the plate.

The rods 2| at the front of the frame are loosely and slidably mounted in holes 22 in each of the horizontal plates l5 and I8, and the opposite ends of each of the rods 2| are enlarged or bent over so as to prevent the rods from sliding outwardly through these holes and yet permit free movement of the rods therein. A U-shaped swinging member 25 is pivoted at its two ends on pins 26 projecting outwardly from the front ends of the two vertical side flanges H of the lower part of the frame. This member 25 is arranged to swing downwardly into the position of Fig. 2 where it forms a support and lock for the sliding bars 2|, whereby the latter are held in their uppermost positions during transportation and non-use. When the device is to be used, the locking member 25 is tipped upwardly into the position of Fig. 1, and such rods 2| as are free to move will then fall to their lowermost positions.

The device may be carried into the manhole of the sewer and set therein so as to straddle the U-shaped tiles or other parts forming the channel 30 of the manhole. The device is usually so located that the rearwardly projecting arms of the frame are-near or rest against the vertical wall 3| of the manhole chamber and close to the outlet pipe -32 opening therefrom, as shown in Fig. 3. Hence the water coming from the inlet pipe into the channel 3!] must pass beneath the framework of this device in order to get to the exit. When the swinging loci: 25 is moved to the position of Fig. 1, the rods 2| which are free to move will slide downwardly through the plates l5 and I8 of the frame until they strike the bottom of the channel 39. In this new position, they form a trap throughout the entire width of the channel.

The water that passes through the manhole must go between the lower ends of the spaced rods 2| and any large lumps of grease, tree roots and the like are caught thereby. If the rods catch so much material as to dam up the water, the latter is free to flow over the top of the framework and into the space formed between the two rearwardly extending side arms of the U-shaped frame. Consequently, no ordinary obstructions can plug up the sewer outlet passage 32 and prevent the water from traveling through the system.

The front of the frame is long enough to straddle the widest channel 30 that may be found in the sewer system. and the rods 2| are selfadjusting for the different widths of channels. If the channel is narrow, only a few of the rods fall into contact therewith. In any case, the upper ends of the rods project to a considerable distance above the top plate l5 of the frame and form an efficient obstruction for larger masses that might otherwise escape over the top of the frame.

When it is desired to remove finer material, such as sand, then the metal plates shown in Figs. l and 5 are employed in conjunction with the apparatus illustrated in Fig. 1. These plates may be suitably shaped and arranged to close the passages between and below the frame members I0 and I2. In the form shown, there are two side plates 36, two front plates 37 and a lower plate 38. The side plates 3%? are shaped to slide between the rods 20 on one side and vertical flanges i6 and I1 and the connecting strips M on the other side. One plate 36 is shown in Fig. 4 in a halfway position. The front plates 37 are each shaped to be located in front of the rods 2| and to form with the side plates and frame a substantially complete dam above the channel. The top of each front plate 31 may fit edgewise against the under edge of the front flange It, as shown, or it may overlap the flange somewhat and rest thereagainst. The bottom of the plate 37 is located behind the front flange H of the lower frame member H. The bottom plate 38 has its lower portion shaped as a semicircle to fit within the channel 30 and close the same. The plate is inserted downwardly through a slot 39 (Fig. 2) between the front flange I1 and the bottom plate It of the lower angle iron frame member i2. The upper end of the plate 38 carries a rearwardly bent flange 40 which rests against the two front plates 37 and thus wedges them in place against the flange it or the rods in the rear thereof.

The plates form a complete weir substantially preventing the passage of water except over the upper frame member It. Thus sand and other material forced downwardly through the sewer system is stopped by the weir and the water is compelled to flow over the top and then down through the space between the side arms of the frame into the outlet pipe 32. Since the rods 28 and 25 project well. above the upper frame It they serve to catch roots and other large bodies that float on the water. Thus it will be seen that whichever way the device is used, the Water may escape freely through the U-shaped framework and the desired obstructions may be caught. Thereafter, it is a simple matter to shovel out the refuse and remove it through the top opening of the manhole. Diiferent sizes of the semi circular plates may be provided to fill whatever size of channel is involved. The movable rods 2|, however, automatically take care of any size of channel since they merely drop down into place as permitted by the channel and the bottom of the manhole.

The swinging lock 25 may be omitted if desired. and the rods 2| may be given a fairly tight fit within the holes 22 of the frame members, so that they may have to be forced manually into position. Although the rods may not move freely and automatically in such a construction, yet they are to be considered as substantially selfadjusting within the scope of my invention.

The operation of the device has been fully set forth as above. It will also be appreciated that various modifications and changes in the constructional details of this device may be made within the scope of this invention, and particularly that I may employ various types of adjustable devices which will fit within sewage channels of different sizes and trap the large bodies, such as roots, and yet permit the water to pass through.

" Hence the above description is to be interpreted as explaining the principles of my invention and a preferred embodiment thereof and not as limitations on the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a frame shaped to straddle the channel in the manhole and a trapping device supported on the frame which has spaced adjustable members depending into and fitting the channel and arranged to trap large bodies while permitting the sewage to flow therebetween.

2. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a frame shaped to straddle the sewage channel in the manhole and spaced rods slidably and loosely supported on the frame which project into the channel and are self-adjusting to fit the same so as to trap large bodies and permit the passage of fluid therebetween.

3. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a frame arranged to straddle the channel of the manhole, spaced rods movably supported on the frame and arranged for self-adjustment to fit within the channel and means for locking the rods in inoperative position.

4. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe,a sewage manhole trap comprising a U -shaped frame having side arms and a connecting front piece, spaced rods secured to the side arms and spaced rods adjustably mounted on the front piece which fit within the sewage channel therebeneath, said U-shaped frame forming a weir when the rods are obstructed so that water may pass over the frame and thence to the outlet pipe of the manhole.

5. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a frame shaped to straddle the sewage channel, spaced rods movably supported on the frame and arranged for self-adjustment to fit within the sewage channel and means for holding the frame spaced from the outlet pipe of the manhole so that if the rods of the frame become clogged with obstructing material the water may pass over the frame and thence to the outlet pipe.

6. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a frame shaped to straddle the channel, spaced rods slidably supported on the frame and arranged for self-adjustment to fit within the sewage channel and plates cooperating therewith which are shaped to obstruct the channel and to form a solid weir.

7. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a U- shaped frame arranged to straddle the channel in the manhole, means providing spaced members projecting above the frame for trapping large bodies and means forming a weir substantially obstructing the passage of fluid within the channel and causing it to flow over the frame.

8. In a sewage manhole having an outlet pipe and an open sewage channel in the bottom of the manhole communicating directly with the outlet pipe, a sewage manhole trap comprising a U- shaped frame, freely slidable spaced rods mounted thereon and projecting into the channel, and a weir including a plate removably fitting within the channel which causes the sewage to flow over the frame, said rods projecting above the weir and obstructing the passage of large bodies thereover.

EVERETT J. PRESCOTT. 

